The fabrication of optical fibers generally involves subjecting a preform to heat and drawing the preform under tension to create the optical fiber. A number of other operations, such as coating, are usually performed as part of the fabrication process. The final optical fiber is typically wound onto a storage spool that can accommodate from many hundreds of meters up to many kilometers of optical fiber.
The optical fiber is inspected during the fabrication process. Such inspections are typically performed on the optical fiber as an isolated strand prior to the optical fiber being wound upon itself on the spool for storage.
Presently, the inspection of optical fibers on storage spools is done manually and is thus a tedious and labor-intensive operation. During the manual inspection, an operator has to visually check the wound fiber for many different types of defects, with some defects being easier to spot than others. For example, abrasions and micro-defects in the optical fiber coating (e.g., bubbles and punctures) are easily missed in view of the optical fiber's bright reflective surface and small diameter. Moreover, one layer of optical fiber on the storage spool can represent over a thousand windings, which makes the inspection process daunting.